The literature review is a staple of scientific research. A literature review is a study that aims to collect and critically assess every source on a particular topic or research issue. This knowledge helps the researcher ascertain the state of current knowledge, and it identifies gaps and deficiencies for future research to address. A literature review also can help researchers develop their own research methods and processes by examining what did - and did not - work in previous research. Many types of literature reviews exist, including narrative reviews, systematic reviews, and meta analyses. When you are trying to figure out the current state of knowledge, the first research step always should be a literature review.
Relevant literature can be found in many places. Sources checked should include scholarly articles, books, and government publications, and also might include grey literature.
This research guide is to help with less formal literature reviews: ones conducted to describe the state of knowledge as part of the research for a paper or brief. In such cases, the literature review may take the form of an initial memo or a multi-page portion of a paper.
Before conducting a literature review, first identify the research question or objective. While your question may evolve as you research, having an initial question will help keep your review on track and manageable in size.
Also consider the review's scope. This includes defining the time frame (are you reviewing literature only from the last five years?) and literature types to be included (peer-reviewed only, or include grey literature?). Keep in mind time limitations, the nature of the question and where relevant information on it may be found, and the resources available to you.